[Prognostic factors of acute radiodermatitis in breast cancer after adjuvant radiotherapy treated with RT3D or IMRT]. / Étude des facteurs pronostiques de radiodermite aiguë dans le cancer du sein traité par irradiation conformationnelle adjuvante avec ou sans modulation d'intensité.

ABSTRACT

PURPOSE: Real life study of prognostic factors of acute radiodermatitis in a monocentric cohort of 200 patients with breast cancer treated with RT3D or IMRT for adjuvant radiotherapy. PATIENTS AND METHODS: This study comprises 200 patients with breast cancer treated with adjuvant radiotherapy, included consecutively. For each patient, their clinical and tumoral characteristics and the irradiation schedule was retrospectively collected. The severity of acute radiodermatitis was also collected, during the treatment and 6weeks after the end of irradiation. The objective was to identify risk factors for acute radiodermatitis grade≥2. RESULTS: The univariate analysis found that a more important BMI (p<0.001), a more important volume of PTV (p<0.001) a normofractionated schedule (p=0.002) were statistically associated to a greater risk of occurrence of grade≥2 acute radiodermatitis. The multivariate analysis found BMI>30 (OR=9.31, p=0.04), light phototype (OR=0.04, p=0.02) and histology other than invasive breast carcinomas (OR=0.07, p=0.04) to be statistically associated to the occurrence of grade≥2 acute radiodermatitis. CONCLUSION: In this monocentric retrospective study, with a prospective collection of the severity of acute radiodermatitis, no grade 3 radiodermatitis has been observed and the frequency of occurrence of grade 2 radiodermatitis was lower than previously published. In contrast to previously published results, IMRT was not associated to a lower risk of grade≥2 acute radiodermatitis. Multivariate analysis found BMI, phototype, and histology to be risk factors of grade≥2 acute radiodermatitis.